Would Mario Andretti try to do the double?

Mario Andretti. (AP)Mario Andretti has been retired for a long time from racing.

But there is one racing opportunity that sort of intrigues the legendary driver.

Speedway Motorsports Chairman Bruton Smith recently suggested offering a $20 million prize for any driver who can win both the Indianapolis 500 and the Coke 600 on the same day, a feat that has never been accomplished.

"I think I might come out of retirement," Andretti joked during an interview this week ahead of his visit to Birmingham for the Legends of Motorsports race at Barber Motorsports Park.

Andretti -- who has won both the Indy 500 and the Daytona 500 -- likes the idea, but thinks it needs some tweaking.

"Twenty million bucks if you win both, but if you compete in both but win one you get $10 million," he said. Otherwise, he said, "the whole idea loses steam halfway through."